/Engine/Source/Editor/UnrealEd/Public/EditorLevelUtils.h
Sets a level's visibility in the editor. Less efficient than SetLevelsVisibility when changing the visibility of multiple levels simultaneously.
static void SetLevelVisibility ( [ULevel](API\Runtime\Engine\Engine\ULevel) * Level, const bool bShouldBeVisible, const bool bForceLayersVisible, const ELevelVisibilityDirtyMode ModifyMode )